Effectiveness and safety of adalimumab compared with leflunomide in patients with Takayasu arteritis: a retrospective cohort study.

OBJECTIVE: This study aims to evaluate the effectiveness and safety of adalimumab (ADA) compared with leflunomide (LEF) in patients with Takayasu arteritis (TAK). METHOD: A retrospective cohort study was performed with the following inclusion criteria: the fulfilment of the 2022 American College Classification/European Alliance of Associations for Rheumatology criteria for TAK, age ≥18 years, and written informed consent. Forty-four patients were treated with LEF (n=28) or ADA (n=16) therapy due to relapsing/refractory disease or toxicity from previous therapy. Patients were evaluated at baseline (T0), at a median of 7.0 months (T1) and at 15.0 months of follow-up (T2). Data regarding disease activity, daily dose of prednisone, side effects and angiographic progression were analysed. RESULTS: LEF and ADA groups had similar features on the baseline visit. However, intravenous methylprednisolone was more frequently prescribed for the ADA group (p=0.019). On T1 and T2 visits, complete response rates were similar for ADA and LEF groups (75.0% and 88.5%; p=0.397 and 62.5% vs 78.3%; p=0.307), respectively. The differences remained non-significant after adjusting for baseline variables by propensity score matching. Although the ADA group had a higher median daily prednisone on visit T1 (p=0.004), it was similar on visit T2 (p=0.595). Similar rates of angiographic progression were observed in ADA and LEF groups (40% vs 25%; p=0.467). Mild-to-moderate adverse events were observed only in the LEF group (17.9%). CONCLUSION: LEF and ADA had comparable outcomes after a median of 15.0 months of follow-up. However, withdrawal from therapy and mild-to-moderate adverse events were only observed in the LEF group.

Monocyte subsets and monocyte-related chemokines in Takayasu arteritis.

The pathogenesis of Takayasu arteritis (TAK) is poorly understood and no previous studies have analyzed monocytes in TAK. This study evaluated monocyte subsets and monocyte-related chemokines in the peripheral blood of TAK patients and healthy controls (HC). Monocyte subsets were identified as classical (CD14+CD16-), intermediate (CD14+CD16dim), and non-classical (CD14dimCD16high) in the peripheral blood. The chemokines CCL (C-C chemokine ligand)2, CCL3, CCL4, CCL5, CCL7, CXCL (C-X-C motif ligand)10, and CX3CL (C-X3-C motif ligand)1 were measured in the sera. Thirty-two TAK patients and 30 HC were evaluated. Intermediate monocytes were higher in TAK than HC [25.0 cells ×106/L (16.7-52.0) vs. 17.2 cells ×106/L (9.2-25.3); p = 0.014]. Active disease was associated with monocytosis (p = 0.004), increased classical (p = 0.003), and intermediate (p < 0.001) subsets than HC. Prednisone reduced the percentage of non-classical monocytes (p = 0.011). TAK patients had lower CCL3 (p = 0.033) and CCL4 (p = 0.023) levels than HC, whereas CCL22 levels were higher in active TAK compared to the remission state (p = 0.008). Glucocorticoids were associated with lower CXCL10 levels (p = 0.012). In TAK, CCL4 correlated with total (Rho = 0.489; p = 0.005), classical and intermediate monocytes (Rho = 0.448; p = 0.010 and Rho = 0.412; p = 0.019). In conclusion, TAK is associated with altered counts of monocyte subsets in the peripheral blood compared to HC and CCL22 is the chemokine with the strongest association with active disease in TAK.

Different epidemiologic profiles of systemic vasculitis between Brazil and Peru-preliminary results in two referral centers from both countries.

Little is known about the epidemiology of systemic vasculitis in South American countries. The aim of this study is to compare the prevalence of systemic vasculitides in two vasculitis referral centers from Brazil and Peru. A cross-sectional study was performed and all patients above 18 years of age, with at least 6 months of follow-up and who met classification or diagnosis criteria for the most common forms of vasculitis, were included. A total of 562 patients with systemic vasculitis were analyzed, 345 (61.4%) from Brazil and 217 (38.6%) from Peru. The frequency of Behçet's disease (37.9% vs. 1.8%; p < 0.0001), Takayasu arteritis (TAK) (25.2% vs. 6.9%; p < 0.0001), and giant cell arteritis (9.8% vs. 0.9%; p < 0.0001) was higher in the Brazilian center than the Peruvian one. On the other hand, the frequency of microscopic polyangiitis (MPA) (67.3% vs. 2.8%; p < 0.0001) and renal-limited vasculitis (2.8% vs. 0.0%; p = 0.009) was higher in the Peruvian center. No differences were found concerning other forms of vasculitis. At diagnosis, Brazilian patients with TAK, granulomatosis with polyangiitis, and MPA were younger than Peruvian patients. Epidemiologic differences in the frequency of systemic vasculitis are observed between a vasculitis referral center from Brazil and another from Peru. Key Points • Significant differences are observed regarding the epidemiologic profile of systemic vasculitis between Brazil and Peru. • MPA is the predominant form of vasculitis in Peru while BD and TAK are the most frequent forms of vasculitis in Brazil. • The age at diagnosis of TAK, MPA, and GPA was lower in Brazilian patients than in Peruvian patients.

Pan American League of Associations for Rheumatology guidelines for the treatment of giant cell arteritis.

Considerable variability exists in the way that health-care providers treat patients with giant cell arteritis in Latin America, with patients commonly exposed to excessive amounts of glucocorticoids. In addition, large health disparities prevail in this region due to socioeconomic factors, which influence access to care, including biological treatments. For these reasons, the Pan American League of Associations for Rheumatology developed the first evidence-based giant cell arteritis treatment guidelines tailored for Latin America. A panel of vasculitis experts from Mexico, Colombia, Peru, Brazil, and Argentina generated clinically meaningful questions related to the treatment of giant cell arteritis in the population, intervention, comparator, and outcome (PICO) format. Following the grading of recommendations, assessment, development, and evaluation methodology, a team of methodologists did a systematic literature search, extracted and summarised the effects of the interventions, and graded the quality of the evidence. The panel of vasculitis experts voted on each PICO question and made recommendations, which required at least 70% agreement among the voting members to be included in the guidelines. Nine recommendations and one expert opinion statement for the treatment of giant cell arteritis were developed considering the most up-to-date evidence and the socioeconomic characteristics of Latin America. These recommendations include guidance for the use of glucocorticoids, tocilizumab, methotrexate, and aspirin for patients with giant cell arteritis.

Distribution of monocytes subpopulations in the peripheral blood from patients with Behçet's disease - Impact of disease status and colchicine use.

The innate immune response has a predominant role in Behçet's disease (BD) pathogenesis, but few studies have assessed monocytes in BD. This study aims to evaluate the profile of monocytes subsets in the peripheral blood of BD patients and healthy controls (HC). Monocytes subsets were identified as classical (CD14+CD16-), intermediate (CD14+CD16dim), and non-classical (CD14dimCD16high) subsets. Patients with BD presented a lower number of total monocytes (p = 0.020) and a lower number (p < 0.0001) of circulating classical monocytes than HC. In contrast, the number of intermediate monocytes was higher in BD patients than HC (p < 0.0001). In BD patients, no associations were observed with the severity of clinical manifestations or therapy. Colchicine was associated with a higher number of non-classical monocytes (p = 0.035). In conclusion, BD patients present an altered distribution of monocytes subsets with a reduction of classical and an increase of intermediate subsets.

Understanding Behçet's Disease in the Context of Innate Immunity Activation.

Behçet´s disease (BD) is a heterogeneous condition consisting of idiopathic systemic vasculitis affecting large and small blood vessels of different types (i.e., arteries, veins, or capillaries). The disease frequently occurs in young adults without gender predilection, differently from several other autoimmune conditions. This challenging illness has recently been proposed by some authors as an example of complex autoinflammatory syndrome. Although much remains unanswered about BD pathogenesis, recent understanding of some aspects of innate immunity have clarified a few issues (and raised others). HLA-B*51 represents the strongest genetic risk factor for BD to date, albeit several other HLA-independent loci have also been associated with the disease. The consistent hyper-reactivity against Streptococcus sanguinis antigens and alterations in oral and gut microbioma suggests that infectious agents may play an important role. Moreover, functional abnormalities of pattern recognition receptors, especially Toll-like receptors in monocytes, have been demonstrated in patients with BD and can be associated with the development of the disease. Neutrophil hyperactivity is one of the most consistent findings in BD pathogenesis, as demonstrated by exacerbated constitutive oxidative burst, chemotaxis and NET formation. However, some studies suggest that the phagocyte-activated status in BD is not primary to the disease itself, but rather restricted to a fraction of patients with severe disease activity, and probably secondary to activating soluble factors carried by serum/plasma from BD patients. Herein we review the state of the art on BD etiopathogenesis with special emphasis on the participation of the innate immune system.

HLA-B*51 and its main subtypes in Brazilian patients with Behçet's disease.

OBJECTIVES: This study aimed to evaluate the frequency of HLA-B*51 and its subtypes in Brazilian patients with Behçet's disease (BD) and healthy controls (HC) and to assess possible associations with disease manifestations. METHODS: A cross-sectional study with sequential BD patients and HC. HLAB*51 presence was determined by sequence-specific polymerase chain reaction (SSP-PCR) and HLA-B*51 subtypes by the Sanger sequencing method. RESULTS: Eighty-three BD patients and 258 HC were evaluated. HLA-B*51 was found in 30.1% of DB patients and in 15.5% of HC (p=0.003). The most prevalent subtypes in DB patients were HLA-B*51:01 (60.0%), HLA-B*51:08 (20.0%), HLA-B*51:22 (8.0%), HLAB* 51:29 (8.0%) and HLA-B*51:02 (4.0%), while HLA-B*51:01 (77.5%) and HLA-B*51:55 (7.5%) were the most prevalent in HC. HLA-B*51 was less frequently found in patients with neurologic involvement (8.0% vs. 29.3%; p=0.034) while HLAB*51:01 was more observed in patients with ocular involvement (93.3% vs. 60.3%; p=0.014). No BD patient with neurologic or vascular involvement presented HLA-B*51:01. HLAB*51:08 was more frequent in patients with vascular manifestations (60.0% vs. 15.4%; p=0.012). In multivariate analysis, HLA-B*51 was an independent risk factor for BD (OR=2.410; 95%CI: 1.332-4.361; p=0.004) and HLA-B*51:08 had an independent association with vascular manifestations of BD (OR = 14.843; 95%CI: 1.550 - 142.115; p=0.019). CONCLUSIONS: The prevalence of HLAB*51 is higher in Brazilian BD patients compared to HC, and it is a risk factor for BD. The HLA-B*51:08 subtype was independently associated with vascular manifestations of BD.

A retrospective cohort study to assess PET-CT findings and clinical outcomes in Takayasu arteritis: does 18F-fluorodeoxyglucose uptake in arteries predict relapses?

The objective of this study is to investigate the use of PET-CT scan with 18F-fluorodeoxyglucose (18F-FDG) as a method to predict outcomes in patients with Takayasu arteritis (TAK), as well as to analyze associations between 18F-FDG PET-CT findings with disease relapses, sustained remission, new angiographic lesions, ischemic events, and changes in therapy for TAK. At baseline assessment, 36 TAK patients underwent 18F-FDG PET-CT scan and maximal standardized uptake value (SUVmax) in arteries ≥ 1.3 was predictive for clinical disease activity. Thirty-two TAK patients were then followed-up for a median 83.5 months. Twenty-three (71.9%) patients developed clinical relapses and new arterial lesions were observed in 14 (43.8%) cases. Disease relapses [85.0% vs. 50.0%, p = 0.049; odds ratio (OR): 5.667; 95% confidence interval (95 CI): 1.067-30.085] and the need for changing immunosuppressive therapy (85.0% vs. 41.7%, p = 0.018; OR: 7.933; 95CI: 1.478-42.581) were more frequently found in patients with SUVmax ≥ 1.3 at baseline compared with those presenting SUVmax < 1.3. No associations were found between SUVmax ≥ or < 1.3 in large arteries at baseline and the development of ischemic events, sustained remission or new angiographic lesions. In multivariate analysis, associations between baseline SUVmax ≥ 1.3 and disease relapses were not independent (hazard ratio: 1.07; 95 CI 0.39-2.92; p = 0.892). In conclusion, arterial SUVmax is marginally associated with disease relapses and with the need to change therapy in TAK. 18F-FDG uptake in large arteries is not associated with the development of new arterial lesions in TAK.

Translation and validation of the Indian Takayasu clinical activity score (ITAS2010) for the Brazilian Portuguese language.

BACKGROUND: The Indian Takayasu Clinical Activity Score (ITAS2010) was developed in 2010 as an assessment tool for disease activity in patients with Takayasu arteritis (TA). It has since been widely used in different studies and in clinical practice for the management of patients with TA. The present study aims to translate the ITAS2010 into Brazilian Portuguese language and to validate it for use in clinical practice in Brazil. METHODS: For this cross-sectional study, the ITAS2010 was translated in accordance with the guidelines described by Beaton et al. and then applied with 27 patients with TA on three assessments by two rheumatologists working independently. To measure interrater agreement, the assessments were performed on the same day within approximately 1 hour. One of the rheumatologists performed a second evaluation of patients with TA within 7 to 14 days to measure intrarater agreement. RESULTS: The correlation coefficient for the ITAS2010 score between the two raters was high (r = 0.916; p < 0.0001), as well as the intraclass correlation coefficient (ICC) [0.918 with a 95% confidence interval (95CI): 0.828-0.962]. The correlation coefficient and the ICC for intrarater agreement were moderate for ITAS2010 (r = 0.633; p < 0.0001 and ICC = 0.594; 95CI: 0.292-0.790). The ITAS2010 at baseline was compared with the physician's global assessment (PGA) and with Kerr's criteria for detecting disease activity in TA. Higher ITAS2010 scores were observed in patients with active and grumbling/persistent disease than in those presenting inactive disease according to the PGA [1.5 (0.0-3.0) vs. 0.0 (0.0-0.0); p = 0.0025]. Patients with active disease according to the Kerr's criteria had also higher ITAS2010 scores than those considered in remission [3.0 (3.0-7.0) vs. 0.0 (0.0-0.0); p = 0.0068]. CONCLUSIONS: The Brazilian Portuguese version of the ITAS2010 is a valid and reproducible tool for the assessment of disease activity in TA and it is an additional tool for the routine evaluation of Brazilian patients with TA.

Silent arterial inflammation during the apparent remission state of Takayasu's arteritis. What do cytokines tell us?

OBJECTIVES: To evaluate serum cytokines as biomarkers of smoldering disease activity in patients with Takayasu's arteritis (TAK) in remission. METHODS: Thirty-four TAK patients with stable disease during the last 6 months and 22 healthy controls (HC) were included in a cross-sectional study. Serum levels of pro-inflammatory, anti-inflammatory, Th1, Th2, Th9, Th17 and Th22 cytokines were measured by the multiplex technique. RESULTS: No significant differences regarding serum cytokine levels were found between TAK patients and HC. Serum TNF-α, IL-17F, IL-21 and IL-23 were higher in patients presenting angiographic type V than in those presenting other angiographic types. Serum IL-17E, IL-17F, IL-22 and IL-23 were higher in TAK patients with previous ischaemic events compared with those without previous ischaemia. No differences in serum cytokines were observed between TAK patients with and without aneurysmal disease in the aorta or among TAK patients without therapy, those under immunosuppressive agents and patients on biological therapy. Independent associations were found regarding angiographic type V and higher serum levels of IL-4, IL-6, IL17A, IL-17E, IL-17F, IL-21, IL-22 and IL-23. Previous ischaemic events were independently associated with higher serum IL-4, IL-17E, IL-22 and IL-23. Daily prednisone dose had an inverse association with lower serum IL-4, IL6, IL-17A, IL-17E, IL-22 and IL-23. The simultaneous use of immunosuppressive and biological agents led to lower serum IL-4, IL-17E and IL-23 levels. CONCLUSIONS: A smoldering inflammatory response with predominantly cytokines involved in Th17 response seems to be ongoing in TAK patients in remission with extensive disease or with previous ischaemic events.

Absence of mycobacterial DNA in peripheral blood and artery specimens in patients with Takayasu arteritis.

The objective of this study was to demonstrate the presence of mycobacterial nucleic acid sequences in peripheral blood and arteries from patients with Takayasu arteritis (TA). Polymerase chain reaction was performed to detect mycobacterial DNA from three different nucleic acid sequences including the insertion sequence (IS) 6110, the 65-kDa heat shock protein gene (HSP65), and the 16S ribosomal RNA (rRNA) gene in peripheral blood from 32 TA patients and in arterial specimens from 10 TA patients. Twenty-eight HIV-negative patients with pulmonary tuberculosis prior to therapy were tested for IS6110 in peripheral blood as positive controls, and 24 blood donors were evaluated as healthy controls (HC). All TA patients were negative for the insertion sequence IS6110 and for HSP65 and 16S rRNA genes in blood samples and in arterial specimens. IS6110 sequence was found in peripheral blood from 22 (78.5 %) patients with pulmonary tuberculosis but not in HC. In conclusion, the strategy of mycobacterial-specific nucleic acid amplification in the peripheral blood and arterial specimens of TA patients was unable to lend support to the association between TA and tuberculosis long suggested in the literature.

(18)F-Fluorodeoxyglucose positron emission tomography and serum cytokines and matrix metalloproteinases in the assessment of disease activity in Takayasu's arteritis.

OBJECTIVE: To evaluate (18)F-fluorodeoxyglucose ((18)F-FDG) uptake on positron emission tomography-computed tomography (PET-CT) and serum levels of different cytokines and matrix metalloproteinases (MMPs) in patients with Takayasu arteritis (TA) and associations with disease activity. METHODS: Serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-2, IL-6, IL-8, IL-12, IL-18, MMP-3 and MMP-9 were measured in 36 TA patients and 36 controls. Maximum standard uptake value (SUVmax) of (18)F-FDG in arterial walls was determined by PET-CT scans. TA patients were classified as active disease, inactive disease and possible active disease. RESULTS: Serum IL-6 and MMP-3 levels were higher in TA patients than in controls (p<0.001). Serum IL-6 was higher in patients with active disease and in patients with possible active disease than in inactive disease (p<0.0001). Patients with active disease had higher serum TNFα levels than patients with inactive disease (p=0.049) while patients with possible active disease presented higher IL-18 levels than patients with inactive disease (p=0.046). Patients with active disease had higher SUVmax values than those with inactive disease (p=0.042). By receiver operating characteristic (ROC) curve SUVmax was predictive of active disease in TA and values ≥1.3 were associated with disease activity (p=0.039). Serum TNF-α levels were higher in patients with SUVmax≥1.3 than <1.3 (p=0.045) and controls (p=0.012). Serum IL-6 levels were higher in patients with SUVmax≥1.3 than in controls (p<0.001). No differences regarding other biomarkers were found between TA patients and controls. CONCLUSIONS: Higher serum IL-6 and TNFα levels as well as higher (18)F-FDG uptake in arterial wall are associated with active TA.

[18F-Fluorodeoxyglucose positron emission tomography and serum cytokines and matrix metalloproteinases in the assessment of disease activity in Takayasu's arteritis]. / Tomografia por emissão de pósitrons com 18F-fluordesoxiglicose e citocinas séricas e metaloproteinases da matriz na avaliação da atividade da doença na arterite de Takayasu.

OBJECTIVE: To evaluate 18F-fluorodeoxyglucose (FDG) uptake on positron emission tomography-computed tomography (PET-CT)-and serum levels of different cytokines and matrix metalloproteinases (MMPs) in patients with Takayasu's arteritis (TA) and associations with disease activity. METHODS: Serum levels of tumor necrosis factor-α (TNF-α), interleukin (IL)-2, IL-6, IL-8, IL-12, IL-18, MMP-3 and MMP-9 were measured in 36 TA patients and 36 controls. Maximum standard uptake value (SUVmax) of 18F-FDG in arterial walls was determined by PET-CT scans. TA patients were classified as active disease, inactive disease and possible active disease. RESULTS: Serum IL-6 and MMP-3 levels were higher in TA patients than in controls (p<0.001). Serum IL-6 was higher in patients with active disease and in patients with possible active disease than in inactive disease (p<0.0001). Patients with active disease had higher serum TNFα levels than patients with inactive disease (p=0.049) while patients with possible active disease presented higher IL-18 levels than patients with inactive disease (p=0.046). Patients with active disease had higher SUVmax values than those with inactive disease (p=0.042). By ROC curve SUVmax was predictive of active disease in TA and values ≥1.3 were associated with disease activity (p=0.039). Serum TNF-α levels were higher in patients with SUVmax ≥1.3 than<1.3 (p=0.045) and controls (p=0.012). Serum IL-6 levels were higher in patients with SUVmax ≥1.3 than in controls (p<0.001). No differences regarding other biomarkers were found between TA patients and controls. CONCLUSIONS: Higher serum IL-6 and TNFα levels as well as higher arterial 18F-FDG uptake are associated with active TA.

Emerging role of high mobility group box 1 in ANCA-associated vasculitis.

High mobility group box 1 (HMGB1) has been suggested to be involved in the pathogenesis of many autoimmune diseases. In addition to its nuclear functions, extracellular HMGB1 released from activated, injured or dying cells becomes a proinflammatory mediator via binding to various receptors on the surface of responding cells. HMGB1 interacts with various systems involved in inflammation, such as the complement system and the coagulation system. Thus, HMGB1 could amplify inflammation and enhance immune responses in pathophysiology of certain diseases. In the past years, HMGB1 has been studied in several vasculitides including antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, Kawasaki disease, Henoch-Schönlein purpura, Takayasu arteritis and giant cell arteritis. Several studies showed that circulating HMGB1 levels are higher in patients with active disease compared with healthy controls, and levels are associated with disease severity. Further studies on pathogenetic mechanisms revealed pathogenic roles of HMGB1 in some vasculitides. Here we review clinical and experimental studies dealing with the role of HMGB1 in vascular inflammation, and its relation to the manifestations and prognosis of specific vasculitides, in particular ANCA-associated vasculitis.

High mobility group box 1 serum levels are increased in Behçet's disease, but not associated with disease activity or disease manifestations.

OBJECTIVES: High mobility group box 1 (HMGB1) is a nuclear protein that acts as an alarmin when released into the extracellular milieu. HMGB1 is a biomarker of active disease in several systemic autoimmune diseases. Behçet's disease (BD) is a systemic inflammatory disorder with a waxing/waning course. The objective of this study is to evaluate serum HMGB1 levels as a possible biomarker for disease activity in BD. METHODS: A cross-sectional study measuring serum HMGB1 levels was performed in 26 BD patients and 20 healthy controls. The Brazilian version of the simplified BD Current Activity Form (BR-BDCAFs) was used to measure disease activity. RESULTS: Serum HMGB1 levels were higher in patients with active disease [3.82 (2.54-6.11) ng/ml], in patients with BD without active disease but still on therapy [2.76 (1.89-5.78) ng/ml] and in patients in remission without treatment [2.66 (1.86-4.70) ng/ml] than in healthy controls [0.96 (0.59-1.39) ng/ml], P < 0.001. Levels were comparable between BD patients with active disease, BD without active disease but still on therapy and those in remission without treatment (P = 0.432). There was no correlation between serum HMGB1 levels and BR-BDCAF(s) (ρ = 0.195; P = 0.339). No association could be found between serum HMGB1 levels and specific disease involvement or therapy. So serum HMGB1 levels cannot be used as a biomarker in BD. CONCLUSION: Serum HMGB1 levels are increased in patients with BD as compared with healthy controls. However, no association was found with disease activity, specific organ involvement or therapy in BD.

High mobility group box 1 levels in large vessel vasculitis are not associated with disease activity but are influenced by age and statins.

INTRODUCTION: Takayasu arteritis (TA) and giant cell arteritis (GCA) are large vessel vasculitides (LVV) that usually present as granulomatous inflammation in arterial walls. High mobility group box 1 (HMGB1) is a nuclear protein that acts as an alarmin when released by dying or activated cells. This study aims to evaluate whether serum HMGB1 can be used as a biomarker in LVV. METHODS: Twenty-nine consecutive TA patients with 29 healthy controls (HC) were evaluated in a cross-sectional study. Eighteen consecutive GCA patients with 16 HC were evaluated at the onset of disease and some of them during follow-up. Serum HMGB1 levels were measured by enzyme-linked immunosorbent assay. RESULTS: In GCA patients at disease onset mean serum HMGB1 levels did not differ from HC (5.74 ± 4.19 ng/ml vs. 4.17 ± 3.14 ng/ml; p = 0.230). No differences in HMGB1 levels were found between GCA patients with and without polymyalgia rheumatica (p = 0.167), ischemic manifestations (p = 0.873), systemic manifestations (p = 0.474) or relapsing disease (p = 0.608). During follow-up, no significant fluctuations on serum HMGB1 levels were observed from baseline to 3 months (n = 13) (p = 0.075), 12 months (n = 6) (p = 0.093) and at the first relapse (n = 4) (p = 0.202). Serum HMGB1 levels did not differ between TA patients and HC [1.19 (0.45-2.10) ng/ml vs. 1.46 (0.89-3.34) ng/ml; p = 0.181] and no difference was found between TA patients with active disease and in remission [1.31 (0.63-2.16) ng/ml vs. 0.75 (0.39-2.05) ng/ml; p = 0.281]. HMGB1 levels were significantly lower in 16 TA patients on statins compared with 13 patients without statins [0.59 (0.29-1.46) ng/ml vs. 1.93 (0.88-3.34) ng/ml; p = 0.019]. Age was independently associated with higher HMGB1 levels regardless of LVV or control status. CONCLUSIONS: Patients with TA and GCA present similar serum HMGB1 levels compared with HC. Serum HMGB1 is not useful to discriminate between active disease and remission. In TA, use of statins was associated with lower HMGB1 levels. HMGB1 is not a biomarker for LVV.